1. Field of the Invention
The invention is a method for administering scopolamine transdermally to inhibit emesis and nausea and a therapeutic system in the form of a bandage structured specifically to carry out the method.
2. Description of the Prior Art
There are several patents that relate to bandages for administering systemic drugs transdermally. In this regard, U.S. Pat. No. 3,797,494 is believed to be the most relevant to the present invention. FIG. 2 of that patent shows a bandage that includes the basic elements of the invention bandage. Indeed, the invention bandage is considered to be a patentable embodiment of the bandage depicted in said FIG. 2. Both bandages are laminates that include a backing, a drug reservoir, a microporous membrane and a contact adhesive layer. However, scopolamine is present in the invention bandage in specific proportions in the contact adhesive layer as well as in the reservoir. Also, the matrix of the reservoir layer of the invention bandage is a gel.
The antiemetic and antinauseant properties of scopolamine and related compounds are known. These properties have been investigated by administering scopalamine and related compounds intramuscularly and orally..sup.1 FNT .sup.1 C. D. Wood and A. Graybiel, "Theory of Antimotion Sickness Drug Mechanisms," Aerosp. Med. 43: 249-52, 1972; and C. D. Wood and A. Graybiel, "A Theory of Motion Sickness Based on Pharmacological Reactions," Clin. Pharm. 11: 621-9, 1970; J. J. Brand and P. Whittingham, "Intramuscular Hyoscine in Control of Motion Sickness," Lancet 2: 232-4, 1970.
Scopolamine acid salts and the C.sub.4 -C.sub.12 esters of scopolamine have been applied topically as antiperspirants..sup.2 FNT .sup.2 F. S. K. MacMillan, H. H. Reller and F. H. Snyder, "The Antiperspirant Action of Topically Applied Anticholinergics," J. Invest. Derm. 43: 363-7, 1964.
The C.sub.4 -C.sub.12 scopolamine esters are reported to be more effective antiperspirants than scopolamine itself because they penetrate better. These esters are the subject of U.S. Pat. No. 3,767,786. They were tested as antiperspirants by applying them as solutions or creams to the forearm and axilla at a dose of 2 mg. Minor systemic responses were observed. Such responses were correlated with systemic responses obtained by administering the esters subcutaneously and it was estimated therefrom that only 5% to 10% of the dermally applied esters was absorbed.
The above mentioned patent suggests using mineral oil as a vehicle for antiperspirant compositions containing the esters, provided there is sufficient water miscible vehicle also present to provide a medium for absorption by the skin. Various surfactants are reported as absorption enhancers for the scopolamine esters.